export interface PageResult<T> { items: T[]; total: number }
export interface Material { id?: number; name: string; category?: string; stock?: number; pricePerDay?: number; description?: string; active?: boolean }
export interface Customer { id?: number; name: string; phone?: string; email?: string; address?: string; company?: string }
export interface Order { id?: number; customerId: number; materialId: number; quantity: number; startDate: string; endDate: string; status: string; totalPrice?: number; createdAt?: string }